On Tue, 7 Mar 2023 08:31:06 +0800 Hillf Danton <hdanton@xxxxxxxx> wrote: > On Mon, 6 Mar 2023 10:28:44 -0500 Steven Rostedt <rostedt@xxxxxxxxxxx> > > On Mon, 6 Mar 2023 09:03:23 +0800 Hillf Danton <hdanton@xxxxxxxx> wrote: > > > > > > PS what sense made by spinning on owner until need_resched() with preempt > > > disabled in the non-rt context? > > > > Not sure what the question you have here is? If need_resched() is set, we > > want to schedule out. > > Given the critical section under mutex could be preempted, what is hard to > understand is the wakeup of a ten-minute sleeper could not preempt a nice-10 > mutex spinner for instance. But it can. Most wakeups are done by interrupts or softirqs. Both of which will happen even if a task is running with preemption disabled. -- Steve
